Predictive Mapping of Electrical Conductivity and Assessment of Soil Salinity in a Western Türkiye Alluvial Plain

Abstract

The increase in soil salinity due to human-induced processes poses a severe threat to agriculture on a regional and global scale. Soil salinization caused by natural and anthropogenic factors is a vital environmental hazard, specifically in semi-arid and arid regions of the world. The detection and monitoring of salinity are critical to the sustainability of soil management. The current study compared the performance of machine learning models to produce spatial maps of electrical conductivity (EC) (as a proxy for salinity) in an alluvial irrigation plain. The current study area is located in the Isparta province (100 km2), land cover is mainly irrigated, and the dominant soils are Inceptisols, Mollisols, and Vertisols. Digital soil mapping (DSM) methodology was used, referring to the increase in the digital representation of soil formation factors with today’s technological advances. Plant and soil-based indices produced from the Sentinel 2A satellite image, topographic indices derived from the digital elevation model (DEM), and CORINE land cover classes were used as predictors. The support vector regression (SVR) algorithm revealed the best relationships in the study area. Considering the estimates of different algorithms, according to the FAO salinity classification, a minimum of 12.36% and a maximum of 20.19% of the study area can be classified as slightly saline. The low spatial dependence between model residuals limited the success of hybrid methods. The land irrigated cover played a significant role in predicting the current level of EC.

A Systematic Review on Digital Soil Mapping Approaches in Lowland Areas

“…However, in refs. [72,78,79], hybrid techniques which incorporate kriging of ML model residuals [99,100] were found to outperform ordinary ML models. The emerging role of hybrid models that combine geostatistical and ML approaches leverage the strengths of both methodologies, enhancing accuracy and prediction performance.…”

Interactive effects of salinity and straw on the soil aggregate stability and organic carbon sequestration in saline soils in the Hetao area, China

“…Salinization due to natural and anthropogenic factors, represents one of the most challenging environmental problems in the world and thus urgently needs to be addressed (Dong, Chen, Petropoulos, Yu, et al, 2022; Kaya et al, 2022; Rath & Rousk, 2015). Soil salinity promotes land degradation, a critical threat to the sustainable development of global agriculture (Chen et al, 2022).…”

Challenges and Opportunities in Remote Sensing for Soil Salinization Mapping and Monitoring: A Review

“…It adversely influences soil structure, nutrient availability, and plant growth, leading to reduced crop yields and, in extreme scenarios, desertification [2,3]. The increasing levels are caused by diverse natural and anthropogenic factors, such as inadequate irrigation practices, fertilizer overuse, and land use changes [4]. In addition, climate change impacts on soil salinization are a significant concern, with weather patterns playing a fundamental role in increasing salt content around the rhizosphere [5,6].…”